igneous
Granite or granitic pebble
Granitic rock, primarily quartz, feldspar, and mica
AI-generated identification · may be incorrectCoarse-grained, speckled gray-tan appearance with visible interlocking crystals; typically Mohs hardness 6–7, vitreous to dull luster, no obvious cleavage as a whole, and specific gravity about 2.6–2.7.
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Physical properties
Coarse-grained, speckled gray-tan appearance with visible interlocking crystals; typically Mohs hardness 6–7, vitreous to dull luster, no obvious cleavage as a whole, and specific gravity about 2.6–2.7.
Formation & geological history
Formed when silica-rich magma cooled slowly deep underground, allowing large crystals to grow; commonly Precambrian to Phanerozoic in age, though this small rounded specimen was likely transported and weathered from an outcrop.
Uses & applications
Used widely as crushed aggregate, dimension stone, countertops, monuments, and landscaping material; small attractive pieces are suitable for teaching or collecting.
Geological facts
The image suggests granite, but the specimen could also be a granitic gneiss or quartz-rich pebble; lighting and resolution prevent confident mineral identification.
Field identification & locations
Look for visible quartz (glassy gray), white or pink feldspar, and black mica in a coarse interlocking texture. Common worldwide, especially in continental mountain belts and glaciated river gravels; a streak, acid, and hand-lens test can help distinguish it from similar rocks.
